Gustav roller



UNITED STATES PATENT OFFICE.

GUSTAV KOLLER, OF VIENNA, AUSTRIA-HUNGARY, ASSIGNOR OF ONE-HALF TO FRANZPGNNINGER, OF SAME PLACE.

PROCESS OF TREATING GLUE AND G ELATlN E MOLDS.

SPECIFICATION forming part of Letters Patent No. 419,779, dated January21, 1890.

Application filed June 8, 1888. Serial No. 276,505. (No specimens.)

To all whom it may concern.- Taking wax casts which fully meet all ar-Be it known that I, GUSTAV KOLLER, cheintistic requirements from glue orgelatine ist, a subject of the Emperor of Austria-Hunmolds has so farproved impossible, as the gal-y, residing at Vienna, in the Province ofmolten wax acts on the mold and dissolves 5 Lower-Austria, in the Empireof Austria-Hunthe superficial portion of the same, so that, gary, haveinvented certain new and useful notwithstanding the fact that the moldsare Improvements in the Process of Treating Glue varnished, only bluntand inaccurate casts and Gelatine Mol'ds; and I do hereby declare can beobtained. the following to be a full, clear, and exact de- By myimproved process of treating and 1o scription of the invention, such aswill enable preparing glue and gelatine molds, presently others skilledin the art to which it appertains to be described, the drawbackshereinbefore to make and use the same. mentioned are fully overcome. Bythis pro- The object of the invention is to provide a cess the outermostor superficial layer of the new and improved process for treating gluemolds, or the whole mass of them, is rendered I5 and gelatine molds forcasting works of art, resistant against being highly heated without themolds being adapted for making serviceprejudice to the sharpness of theforms and able plaster and wax casts and permitting of to the elasticityof the molds, so that plaster pouring alloys of a low melting-pointdirectly casts may be allowed to coolwithin the molds, into them. themolten wax can be heated to a tempera- 20 The invention consists oftreating the surture of nearly 212 Fahrenheit, or molten alface of themold with strong oxidizers and afloys the melting-point of which is notmuch terward exposing the same to the action of above this temperaturemay be poured into the light. the molds without alteration of theirsurface.

The elastic glue and gelatine molds, on ac- In this way it is possibleto use elastic glue 25 count of their cheapness of manufacture orgelatine molds when making wax casts or and of the sharp negatives theyafliord of the fillings necessary in casting brass upon acore. mostartistic designs, have superseded in all The necessary resistance isgiven to molds branches of reproducing plastic objects the by treatingtheir surface with energeticallyformerly-used plaster-of-paris molds.oxidizing substances. For this purpose an 0 The glue and gelatine moldsas heretofore aqueous solution of anhydrous chromic acid, constructedhave a serious drawback, which chromates or permanganates of alkalies,or becomes very apparent when taking plaster nitrate of silver can beused to great advanor stucco casts from the molds or when retage. Afterhaving coated the molds one or moving wax casts. more times with one orthe other of said solu- 5 35 As is well known, plaster-of-paris and alltions they are exposed to daylight, or, if neccompositions containingthis substance heat essary, to an artificial light, and so allowed towhen hardening in the molds, so that the updry, which completes theprocess. The oxpermost layer of glue or gelatine mass is idizing layerwhich is thus formed imparts to melted. The preventive measuresheretothe mold astrong resistance against heat with- 9 '40 fore takenagainst this, by coating the molds out impairing in the least theneatness of the t with oil varnish and adding alum to the plasforms. Byapplying one or more concentrated tic mass used for the cast, do notaffect this solutions of the said strong oxidizers to the surdrawback,as the varnish stands a relatively face of the molds a greater or lessnumber of small number of casts only and as the additimes and byexposing the molds a longer or 5 tion of alum hastens the solidificationof the shorter period of time to the action of light superficial portionof the cast, thus admitting a thicker or thinner layer of the oxidizingsubof its being taken out of the mold before it is stance is obtained,according to the special retoo highly heated,but causing crystals toform quirements. After the molds are provided on the surface of thecast, which, although with a layer of the oxidizing substance the 50they do not render it wholly unserviceable, molds maybe coated with athin layer of varmar its aspect. nish.

When it is not desirable to use the material of unserviceable moldsagain,the glue or gelatine maybe dissolved in one of the aforesaidsolutions instead of dissolving it in water, as usual. The molds areformed in the usual way from the solution of glue or gelatine thusobtained, and afterward they are exposed to the action of. the light, sothat the whole mass of the mold is oxidized and rendered resistantagainst heat. It has been found by experiment that an aqueous solutionof anhydrous chromic acid gives the best results. By applying thisliquid from two to six times to the surface of the molds andsubsequently exposing the molds to the action of light during six hours,molds are obtained which do extremely well for plaster or stucco and waxcasts, as well as for work on reliefplates and statuary. It is obviousthat molds of the desired kind, owing to their resistance against heat,can be directly used for taking casts in alloys the melting-point ofwhich is not much above 212 Fahrenheit.

The glue or gelatine material of dried-up or nnserviceable molds inwhich the superficial layer only has been treated with the saidoxidizers can generally be used again. To this end the molds are out topieces and said pieces are boiled in water, and finally the mass iscaused to pass through a sieve, so that the 30 oxidized portions will beretained by the sieve,

as the said oxidized portions are less soluble in water than genuineglue or gelatine.

Having thus fully described my invention, I claim as new and desire tosecure by Letters 35 Patent l. The herein-described process for treatingglue or gelatine molds, consisting in treating the surface of the moldsto strong oxidizers and afterward exposing the same to the ac- 40 tionof light, substantially as described, and for the purpose set forth.

2. The herein-described process for treating glue or gelatine molds,consisting in dissolving the glue or gelatine in an aqueous solu- 45tion of energetic oxidizers, then forming the molds in the usual way,and finally exposing the same to the action of light, substantially asdescribed.

In testimony whereof I affix my signaturein 5o presence of twowitnesses.

eUsiAv KOLLER.

Witnesses:

EDMUND J USSEN, OTTO SCHIFFEN.

